By sampling location, time, speed, and other information of one or more moving objects, trace data of the moving objects can be formed based on a chronological order of the sampled information, which includes, for example, traffic trace data, animal migration data, climate or airflow data, personnel movement data. Using traffic trace data as an example, by utilizing a certain positioning technology, such as video surveillance and image identification, WiFi positioning technology, RFID tag technology, or GPS technology, trace data for movements of vehicles and pedestrians may be obtained. There is a great demand on analyses and visualization of trace data for smart city, traffic management, crowd geographic profiling, and other services based on location (Location Based Service, LBS).
In certain technologies, for visualizing trace data, a server can be used to render a heat map based on the trace data and zoom-level, and then load tiles of the heat map (e.g., visualization processes of a heat map in Baidu map and visualization of Twitter data in Mapbox). However, because servers for those technologies have rendered a heat map based on a large amount of data, a terminal device downloads and assembles the heat map according to the size ratio of the heat map from the servers instead of accessing real-time data. Thus, image quality of the heat map can be poor due to a large amount of data transmitted through the Internet.
In certain technologies, for visualizing trace data, still images can be formed directly from the trace data (e.g., analysis and processes for geographical data in Geographic Information System, GIS). However, time needed to render images increases with the amount of data. Although these technologies provide quality images, they do not allow users to analyze the content and data of the still images independently and interactively.
In certain technologies, trace data can be directly visualized (e.g., analyzes of taxi in New York Times). Such methods are often used for news, customized based on needs, and data are prepared by data engineer, where the data are prepared into a small-size format and volume, and do not provide a high-level quality.
For technologies that provide to terminal devices trace images downloaded from backend servers, the trace images formed by backend servers suffers from delays, which cause the terminal devices not able to display the trace images in real time. There are still no good solutions for such issues.